Clutch Unit with Phase Alignment and Centering Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional clutch units fail to securely lock the output shaft during impact loads or continuous alternating rotational torque inputs, leading to potential seat height adjustments and instability in vehicle seat lifters.
Innovation Solution
A clutch unit design featuring a stationary female gear member that meshes with a rotatable male gear member on the output shaft, utilizing alignment and centering parts to maintain lock engagement even under impact or alternating torque conditions, with a C-shaped elastic member for assembly and axial alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cylindrical rollers are used to lock the output shaft through wedge clearance engagement, then the structure is simple and easy to manufacture, but the locked state cannot be maintained under impact loads or continuous alternating torque inputs
Solution Approach 1:
The clutch part is divided into two independent functional modules: a first clutch part with cylindrical rollers for normal reverse torque locking, and a second clutch part with wedge-shaped blocks for impact load locking. Each module operates independently through its own engagement mechanism, allowing the system to handle different load conditions with specialized structures rather than requiring a single complex mechanism.
Solution Approach 2:
The stationary member acts as an intermediary between the input member and output member, providing a fixed reference frame for both the first and second clutch parts. The stationary member includes both a first wedge clearance for cylindrical roller engagement and a second wedge clearance for wedge-shaped block engagement, mediating the different locking mechanisms in a unified structure.
2Reliability
If only cylindrical rollers are used in the brake-side clutch part, then the manufacturing cost is low, but the output shaft gradually rotates under continuous alternating torque inputs causing seat height to decrease
Solution Approach 1:
The braking function is segmented into two distinct mechanisms: cylindrical rollers for normal operation and wedge-shaped blocks for impact and continuous alternating torque conditions. The wedge-shaped blocks with their inclined surfaces provide progressive engagement that prevents gradual rotation, while the cylindrical rollers handle routine locking operations.
Solution Approach 2:
The wedge-shaped blocks utilize asymmetric inclined surfaces that engage differently depending on the direction and magnitude of applied torque. The inclined surfaces are designed to provide increasing engagement force under continuous alternating torque, preventing the gradual rotation that occurs with symmetric cylindrical roller engagement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design effectively locks the output shaft during impact and alternating torque inputs, preventing seat height changes and ensuring stability in vehicle seat lifters by maintaining engagement through phase alignment and centering mechanisms.
Implementation Method 1
there is hysteresis of elastic deformation on the output shaft on which rotational torque is loaded, the outer ring and the cylindrical rollers
Data Source
AI summary
A brake-side clutch part includes an outer ring whose rotation is restricted and an output shaft from which rotation is output. The outer ring is provided with a slide gear that meshes with the output shaft when rotational torque is cut off and releases a meshing state with the output shaft when rotational torque is transmitted. The output shaft is provided with an inner gear that meshes with the slide gear so as to be slightly rotatable. An alignment part that aligns a phase of the inner gear with that of the slide gear when rotational torque is cut off, and a centering part that returns the inner gear to a neutral position with respect to the output shaft when rotational torque is transmitted are provided between the inner gear and the output shaft.